package cn.tedu.sp06.fallback;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

@Component
public class OrderFB implements FallbackProvider {
    //针对那个服务应用降级类
    //针对服务id
    //      item-servce - 只针对商品服务降级
    //      *  - 对所有服务降级
    //      null -  对所有服务降级
    @Override
    public String getRoute() {
        return "order-service";
    }
    // 返回的降级响应,封装在response
    //根据自己应用的需求,可以返回任意的响应数据
    // - 错误提示
    // - 缓存数据
    // - 执行业务运算返回结果
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();
            }

            @Override
            public void close() {
                //不需要关闭 BAIS 流是内存数组的流 不占内存资源
                // 不需要close()释放资源
            }

            @Override
            public InputStream getBody() throws IOException {
                String json = JsonResult.err().code(500).msg("系统服务故障").toString();

                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders h = new HttpHeaders();
                h.add("Content-Type", "application/json;charset=UTF-8");
                return h;
            }
        };
    }
}
